The invention generally relates to wireless communication systems. In particular, the invention relates to implementations of sub base stations and user equipments in wireless communication systems.
FIG. 1 is a simplified illustration of a wireless communication system. A user equipment (UE) 22, such as a cellular phone, and a base station 20 send communications to each other. Communications from the base station 20 to the UE 22 are referred to as downlink communications. Communications from the UE 22 to the base station 20 are referred to as uplink communications. The physical structure of the communications is based on the type of wireless system deployment, such as analog frequency division duplex (FDD), FDD using code division multiple access (CDMA), time division multiple access (TDMA), TDMA using CDMA or time division duplex (TDD) using CDMA.
The UE 22 communications are sent to another user via a public switched telephone network (PSTN) 30. The communications are transferred from the base station 20 to the PSTN 30, typically, via a Node-B 24, a radio network controller (RNC) 26 and a core network 28.
It is desirable to have alternate implementations of user equipments in wireless systems.